Hazardous drinking (HD) is a major public health burden worldwide with significant morbidity and mortality. The prevention and treatment gap associated with this global burden requires that efficacious interventions be scaled-up, leveraging existing platforms and participation of policy makers ready to apply and sustain evidence-informed policies over time. To reduce HD, the WHO recommends using Screening, Brief Intervention, Referral to Treatment (SBIRT) and the mental health Gap Action Programme guidelines (mhGAP). As low- and middle-income countries (LMIC) embrace SBIRT and mhGAP for community-based HD services (HDS), a main scale-up challenge is ensuring effectiveness, fidelity, and sustainability of services. Mobile health technology (mHealth), such as the mSBIRT app developed by members of our team, is a promising tool for widespread cost-effective delivery of evidence-based HDS by community health workers (CHWs) because of its potential to increase fidelity, effectiveness, and sustainability. The proposed project, Community I-STAR (Implementation of SBIRT using Technology for Alcohol use Reduction) Mozambique, will leverage the following existing Mozambique Ministry of Health (MoH) programs: (1) a task-shifting strategy training psychiatric technicians (PsyTs) to use the mhGAP; (2) the WHO-funded epilepsy community program delivered by CHWs; and (3) an mHealth program for malaria, pneumonia, and diarrhea (inSCALE - Innovations at Scale for Community Access and Lasting Effects). These currently operating programs set the stage for the use of mSBIRT by CHWs to deliver community HDS in Mozambique and generate policy for scale-up of government-funded community HDS harnessing existing human resources. Community I-STAR Mozambique comprises three phases: 1) mSBIRT adaptation, 2) a cluster-randomized trial, and 3) scale-up of the most cost-effective intervention. After a formative phase to adapt mSBIRT to Mozambique?s context/culture, we will conduct a 2- year, cluster-randomized, hybrid effectiveness-implementation type 2 trial in 12 districts: 6 districts randomized to receive mSBIRT and 6 to an SBIRT Conventional Training and Supervision strategy (SBIRT-CTS), with both arms delivered by CHWs. The arm showing higher cost-effectiveness in the 2-year trial will be scaled up to the other 6 districts for 12 ?cross-over? months. Throughout the trial and the ?cross-over? scale-up, qualitative and process data will complement quantitative assessments to examine implementation, sustainability, and scale-up. Our approach redefines work roles without requiring new human resources, and it comports with the MoH?s commitment to implementing HDS. We will use evidence-based practices (SBIRT) to a) build capacity for complete task-shifting of sustainable community-HDS practices; and b) use implementation tools to examine implementation and effectiveness of two SBIRT delivery strategies followed by evaluation of scale-up of the most cost-effective strategy. Community I-STAR Mozambique will scale-up a cost-effective, sustainable program and inform policy applicable to Mozambique and other LMICs.